NY Plot Was One of Most Serious Since 9/11: Holder

Attorney General says more arrests are coming in al-Qaeda plot

Receive the latest local updates in your inbox

The New York-based terror plot the feds say they disrupted last month was one of the most serious in the U.S. since the 9/11 attacks, Attorney General Eric Holder declared.

Although just one suspected plotter, airport shuttle driver and coffee cart man Najibullah Zazi, has been arrested so far, Holder vowed to bring to justice all of Zazi's cohorts. He would not give a timeline when more arrests might come or say how many people might be involved.

"There are people both in this country and also abroad who are committed to harming the American people and they're actively plotting to do so," Holder said.

Zazi has been charged with conspiring to detonate bombs in the U.S., and two others have been charged with lying to investigators in the case.

Court papers charging Zazi with plotting to use weapons of mass destruction allege that at least three people helped him buy beauty products containing peroxide and acetone in suburban Denver. The chemicals can be used to make homemade bombs, federal officials said.

Officials would not say anything about the whereabouts of the possible accomplices or the bomb-making materials. As first reported by NBCNewYork.com last month, investigators have fanned out across the Denver area and New York City, going to beauty shops, home improvement stores and neighborhoods Zazi frequented looking for possible accomplices. As many as eight accomplices were being watched, according to sources close to the investigation.

Zazi, 24, has admitted he received weapons training from al Qaeda in Pakistan. He is at the center of what federal officials said could be a plot to blow up subways or other targets in New York City. He and his father were arrested in Denver while a Queens imam, Ahmad Wais Afzali, 37, was arrested in New York and also charged with lying to the government during the terror probe.

Afzali was released last week on $1.5 million bond secured by his father's home. He will be required to submit to electronic monitoring and he can visit his mosque.

A joint terrorism task force is continuing to canvas the New York City area to see if chemicals or bomb making equipment might be stored in our area, the sources told NBC New York.

Federal officials said Zazi drove from Denver to New York on Sept. 9 and a search found him in possession of a bomb-making manual, batteries, a scale, and other equipment that could be used to make explosives.